This application is directed to corona device of the type generally used in depositing charges on chargeable surfaces of an electrostatic reproduction machine. More particularly, this invention is directed to a corona charging device of the type disclosed in copending application Ser. No. 748,805 in the joint names of T. Davis and G. Safford and assigned to the assignee of the present invention and more particularly to an arrangement for making electrical contact with, and placing under tension a dielectric coated wire coronode of the type disclosed therein.
One arrangement for mounting this type of corona device is shown in the aforementioned copending application in which the interior wire is extended beyond the ends of the dielectric sleeve and wound about a screw which is turned to render it taut. Variations of this arrangement are shown in U.S. Pat. No. 3,908,127. These methods are currently used in many commercial xerographic machines using bare wire corona electrodes. In such an arrangement the wire must be sufficiently strong to withstand the tensioning force.
An attempt at providing a suitable tensioning arrangement for a dielectric coated coronode is shown in copending application Ser. No. 751,827 in the name of J. Laing, also assigned to the same assignee as the present application. In that arrangement, the end portions of the dielectric coating are formed into enlarged masses which are biased or pressed against to hold the coronode taut. Electrical connection to the inner wire in this arrangement is by means of direct contact with the wire which is extended beyond the dielectric on at least one end of the coronode. This latter method suffers from the disadvantage of complicating the manufacture of the coronode itself, while nevertheless requiring the use of a separate contacting means to the wire.
A method of maintaining a tension on a conductive wire coronode of an corona charger of the type used in electrostatic reproduction machines is shown in copending application Ser. No. 783,359 in the name of Donald Weikel, also assigned to the assignee of the present application. In this application is disclosed a tensioning arrangement including a coil spring coaxially carried by one end of a corona wire, which spring is compressed or loaded between a fixed surface of a mounting block and a mass carried on the corona electrode outboard of the spring.
Yet a further arrangement for mounting a corona electrode of the bare wire or coated wire type is disclosed in concurrently filed application Ser. No. 802,165, also assigned to the assignee of this application, in the joint names of F. Hubble and J. Tasseff. This instant invention is directed to an alternative arrangement for incorporating a dielectric coated wire into the support and tensioning arrangement disclosed in the last named application.